Heat treating machine



1958 Q. M. BLOOM Erm. 2,848,213

HEAT TREATING MACHINE 6 Sheets-Sheet 1 Filed June 8, 1955 INVENTORS.QUENTIN M. BLOOM SAMUEL H. HERMAN ATTORNEY Aug. 19, 1958 Q. M. BLOOMEII'YAL 2,848,213 I HEAT TREATING MACHINE Filed June 8, 1955 6Sheets-Sheet 2 INVENTORS. QUENTIN M, BLOOM BY SAMUEL H. HERMAN ATTORNEY.

1958 Q. M. BLOOM El'AL 2,848,213

HEAT TREATING MACHINE 6 Sheets-Sheet 3 Filed June 8, 1955 INVENTORS.QUENTIN M. BLOOM SAMUEL H.HERMAN ATTORNEY.

Aug. 19, 1958 Q. M. BLOOM irrAL ,2

HEAT TREATING MACHINE Filed June 8, 1955 6 Sheets-Sheet 4 INVENTORJ'.QUENTIN M. BLOOM BY SAMUEL H. HERMAN ATTORN EY.

Aug. 19, 1958 Q. M. BLOOM EI'AL 2,

HEAT TREATING MACHINE Filed June 8, 1955 6 Sheets-Sheet 5 FIG.8

ATTORNEY.

Aug. 19,1958 M, BLOOM HA 2,848,213

I -IEAT TREATING MACHINE 6 Sheets-Sheet 6 Filed June 8, 1955 wfi m w M OM w m a w T m E n u o N B H n n m n n W N M H m m I N L n l E m w m U nn E M u u WM u n N9 1 -L ATTORNEY.

United States Patent HEAT TREATlNG MACHINE Quentin M. Bloom, HuntingdonValley, and Samuel H.

Herman, Philadelphia, Pa., assignors to Selas Corporation of America,Philadeipliia, Pa., a corporation of Pennsylvania Application June 8,1955, Serial No. 513,936

14 Claims. (Cl. 2664) The present invention relates to the heattreatment of hardenable ferrous metal articles, and more particularly toapparatus by means of which said articles are moved continuously througha path along which are located pieces of apparatus that successivelyperform various steps in the heat treatment of the article.

The present invention includes an endless conveyor that has attached toit a plurality of work supporting members upon which the pieces to beheat treated are mounted. These members are moved to dilferent positionswith respect to the conveyor at various points along the conveyor pathin order to facilitate the handling of the work as well as to locate itproperly for the various steps of the heat treatment that are performedupon it.

The apparatus is designed to handle articles of various shapes andcompositions. It is particularly designed, however, for use in the heattreating of shell blanks after forging, and, by way of example, will bedescribed as being used for that purpose.

It is a specific object of the invention to provide a machine for heattreating shell blanks from the residual forging heat.

It is an object of the invention to provide a machine which will handlearticles to be heat treated, and to move them in sequence through a pathwhere different operatiOns are performed on them at different stationsalong the path. It is a further object of the invention to move metallicobjects through a path and at sequential stations in the path, even outtheir temperature, quench them, temper them and cool them in a pluralityof steps.

Another object of the invention is to provide a conveyor for movingobjects through a path in which the object supporting portions of theconveyor are tilted to various positions to facilitate placing theobjects thereon and to carry them through the work zones in the properposition with relation thereto.

A further and more general object of the invention is to provideapparatus for heat treating individually a plurality of metallicobjects, one after the other, in a duplicate fashion.

The various features of novelty which characterize our invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages and specific objects attained with its use,reference should be had to the accompanying drawings and descriptivematter in which we have illustrated and described a preferred embodimentof the invention.

In the drawings:

Figure 1 is a plan view showing the entire apparatus;

Figure 2 is a view taken on line 2-2 of Figure 1 showing the conveyordriving mechanism;

Figure 3 is a view taken on line 3-3 of Figure 2 showing a portion ofthe driving mechanism in plan;

Figure 4 is a viewtaken on line '44 of Figure 2 showing one side of aportion ofthe conveyor;

Figure 5 is a view taken on line SS of Figure 1 showing the loadingplatform;

Figure 6 is a view taken on line 6-6 of Figure 1 showing a portion ofthe balancing furnace and the quench tank;

Figure 7 is a view taken on line 7-7 of Figure 1 showing a sectionthrough the tempering furnace;

Figure 8 is a view taken on line 88 of Figure 1 showing the sectionthrough the air cooling mechanism;

Figure 9 is a view taken on line 99 of Figure 1 showing a sectionthrough the water cooling apparatus, and

Figure 10 is a view taken on line 10-10 of Figure 1 showing thedischarge platform.

Reference is first made to the plan view of the entire apparatus inFigure 1 wherein the position of the various parts with relation to eachother is shown. The various work pieces that are to be operated upon bythe apparatus are moved through a path on a conveyor 1 that is guided byidler sprockets 2 and 3 and a driven sprocket 4. The work starts from aloading station 5 where it is placed on the conveyor in a horizontalposition. Immediately beyond this station, the work is moved to avertical position and through a temperature equalizing furnace 6. As thework leaves the furnace, it is moved to or below a horizontal positioninto a quench tank 7. From the quench tank, the work is returned to itsVertical position and moved in sequence, while in this position, througha tempering furnace 8, an air cooling station 9 that is supplied withair by a blower 11 and a Water cooling station 12. Thereafter, thecooled work is removed from the conveyor onto a platform at a dischargestation 13.

The conveyor is best shown in Figures 2, 4 and 5. It will be seen thatthe conveyor includes a roller chain 14 that passes around the sprockets2, 3 and 4. This chain is connected by brackets 15 with a numberofcarriages 16 that ride along a track formed of angle-irons 17. The trackis above and parallel to the path through which the chain is moved. Eachcarriage is identical and is provided with four rollers 18 that aremounted in pairs on the ends of shafts 19 which in turn are journaled inthe carriage. Extending downwardly and to one side of the "carriage is asupporting member 21 that has a shaft 22 therethrough parallel to thedirection of movement .of the carriage and the conveyor chain. AU-shaped work supporting bracket 23 is pivoted on each end of shaft 22,so that each carriage has two brackets. Each bracket is provided with aprojection 24 extending outwardly from its lower corner for a purpose tobe described below, while the upper portion of each bracket is formed asa socket which has fastened in it a work supporting rod 25. Surroundingthe rod 25 and loosely mounted thereon is a roller or collar 26.

The brackets are normally held in the vertical position shown in Figures2 and 5 which position is accurately adjusted by means of engagementbetween a projection 27 on the bracket and the end of a bolt 28 that isthreaded into a socket 29 on the carriage. It will, therefore, be seenthat as the chain is moved by the sprocket 4, the carriages will ridealong track 17 and carry with them the work supporting members 23. Thesemembers may be moved around the pivots 22 relative to the carriages tovarious positions depending upon the location of a particular carriagein its path of travel.

The conveyor is moved to carry the work past the various stations byrotating sprocket 4 counterclockwise in Figure 1. To this end, thesprocket, as shown in Figures 2 and 3, is keyed to the upper end of ashaft 31 that is journaled for rotation in bearings 32 and 33. Alsokeyed to the shaft is a ratchet plate 34 that is rotated intermittentlyby a pawl 35 on an arm 36 that is pivoted for oscillation around shaft31. The pawl is kept in engagement with the edge of the ratchet plate bymeans of an arm 37 extending rearwardly therefrom with the outer end ofthe arm biased in a counterclockwise direction by means of a spring 38.Arm 36 is oscillated around shaft 31 by a piston rod 39 that is pivotedto the arm and which has a piston on its other end that is received in adouble acting cylinder 41. The left end of this cylinder is pivoted tothe frame at 42, as is shown in Figure 1. Movement of the arm 36 islimited by stops 43 and 44.

In operation, air is admitted to the left end of cylinder 41 therebyacting through piston rod 39 to move the arm 36 against stop 44. In thisposition of the arm, the pawl falls behind one of the teeth on ratchet34. Air is then admitted to the right end of cylinder 41 to producemovement of arm 36 in a counterclockwise direc tion. This arm actsthrough pawl 35 to rotate sprocket 4 and thereby index the chain of theconveyor one step. Air is admitted to opposite ends of cylinder 41 inany conventional manner at predetermined intervals of time. The variousparts that act on the work holders and the work carried thereby are solocated relative to the conveyor that they can act on the work holdersduring periods of rest or for a predetermined length of timerespectively.

As the carriage is moved into the loading position 5. the various worksupporting brackets and rods 25 are in a substantially horizontalposition as shown in Figure 1 and by one of the holders in Figure 5. Theexact position of the work holders is determined by the engagement ofcollar 26 on the shaft 25 and a rail 45 that follows the path of theconveyor. While the work holders are in their horizontal position, thework, which is in this case shown as being a hot forged shell, is movedfrom a loading platform 57 to the rods 25. The work holders are thenmoved from the horizontal position in Figure 5 to the vertical positionthereof before being carried along by the conveyor. The work holders areshifted from their horizontal to their vertical position by a liftingmechanism that is mounted on a stand 46 located adjacent to the conveyorand located to engage a work holder in a position it will assume betweenindexmg movements.

As shown in Figure 5, the lifting mechanism is provided with a liftingbar 47 having a roller 48 on the end thereof which engages theprojection 24 of the supporting bracket 23 in front of it. Bar 47 ismounted for parallel movement in a horizontal direction by a pair oflinks 49 and 51 that are pivoted at their lower ends to the bar and attheir upper ends to the frame. The pivot for link 51 is a shaft to whichit is attached and which also has an arm 52 attached to it and extendingin the opposite direction. The outer end of arm 52 is connected to apiston rod 53 whose other end has a piston on it that is received incylinder 54. The lower end of the cylinder is mounted at 55 foroscillation around a bracket on stand 46. There is also provided a stop56 to limit the movement of'ann 47 to the right.

Periodically, while the conveyor is at rest, air is introduced into theupper end of cylinder 54 thereby to produce movement of arm 47 to theleft in Figure 5. As this movement continues, roller 48 engages aprojection 24 of a work holder in a horizontal position and moves thiswork holder around shaft 22 as a pivot until the holder or bracket 23 isin its full line position. As the bracket 23 is moved in a clockwisedirection, it will reach a point where its center of gravity is to theright of shaft 22 and will then fall into its vertical position. Sincethe center of gravity of the bracket plus the work mounted on the upperend of shaft 25 is to the right of pivot 22, this bracket will remain inposition until such time as it is positively moved in a counterclockwisedirection. At times the carriages may have a tendency'to tilt out oftracks 17 as the brackets are being pivoted if the work is heavy. Thiscan be overcome by placing a cover over the tracks at the points wherethe pivoting of the brackets 23 takes place. The cover can take theform;

of a channel such as the forming the bottom of duct 83 in Figure 6.

After the work supports have been moved into their vertical position,continued travel of the conveyor will move them into the furnace 6. Asbest shown in Figure 6 of the drawing, this furnace has a narrowentrance 58 which leads into a narrow, elongated furnace chamber 59 thatis heated by burners 61 located in the sides thereof. The furnace isconstructed in accordance with ordinary furnace practice, and theburners are preferably of the type disclosed in Hess Patent 2,215,079.This is a relatively short furnace and in the application shown is to beused only for evening out the temperature of the various sections of theshell. Beyond the burners, at the exit end of the furnace,.there isprovided an arcuate hood 62 having an arcuate portion 63 which, ineffect, forms an L-shaped extension to the furnace chamber and throughwhich the work supporting members are moved from their vertical positionto a position slightly below the horizontal in order to place the workin a quench tank 7. As explained above, the work holders remain in avertical position due to their construction. They are moved from thisvertical position when they reach the hood portion 62 by means of alowering mechanism which includes a first portion that moves the holdersout of the vertical sufiiciently for them to have a tendency to fall ina counterclockwise direction in Figure 6, and a second portion thatcontrols the lowering of the work holders to place the work in thequench liquid in tank 7.

The first portion of the lowering mechanism includes a pusher 64, theouter end of which is guided by a structural member 65 and the inner endof which is connected to a piston rod 66 having a piston on the endthereof that is received in a cylinder 67. When a work holder or bracket23 is at a position of rest in which it is aligned with the portion 63of hood 62, fluid is introduced in the right end of cylinder. 67 to movepusher 64 against the upper portion of work holder and thereby move thisholder to the left in Figure 6. At this time, the roller 68 on arm 69that controls thelowering of the work holder, is in its left or dottedline position, so that it will be engaged by projection 24. Arm 69 issupported for parallel movement by a pair of links 71 and 72, the latterof which is fastened to a shaft 73 that has an arm 74 also fastened toit and projecting in the opposite direction from link 72. The outer endof the arm 74 is attached to piston rod 75 having a piston on it that isreceived in cylinder 76 the right end of which is pivoted at 77. Afterthe work holder 23 has been moved to bring projection 24 into engagementwith roller 68, fluid will be released from the left end of the cylinderand introduced into the right end thereof at a rate to control thelowering or counterclockwise movement of the holder. This continuesuntil the right end of arm 69 is in engagement with a stop 78. At thistime, collar 26 on the work holder is resting on a track 79 extendinglengthwise through the quench tank. At the same time, the side of theshell blank will engage a pair 'of rods 81, and its end is moved againsta shield 82 as it goes below the horizontal. The shield serves toprevent the work from falling oil? the work holder and also extendslengthwise through the quench tank. It is noted that the carriages 16are covered by a water cooled duct or chamber 83 for the extent of theirtravel through the furnace. This is to prevent heat from the furnacebeing reflected downwardly through the slot in the floor thereof againstthe conveyor mechanism and also to protect the pivot 22 from the heat.

Continued indexing movement of the conveyor moves the. various workholders and the work carried thereby through the quench tank until theyreach a position in front of a lifting mechanism 84 that is similar tothe mechanism 68 to 78 inclusive but is intended to operate in theopposite fashion. Mechanism 84 serves to return the work holders and thework carried thereby to a vertical position, so that the quenching fluidcan drain from the work and the holders. It is noted that this liftingmechanism can be shifted to various points along the quench tank for thepurpose of removing the work from the quench liquid after varyingperiods of time required for the work to be reduced sutficiently intemperature. The more the work is to be cooled in the quench, thefurther toward the end of the tank 7 mechanism 84 will be located. Inany event, this mechanism will be located at least two indexingmovements from the end of the tank in order to give the work time todrain before it continues its movement through its path.

After the work holders leave the quench, they pass around sprocket 3 andinto reheating or tempering furnace 8 shown in Figure 7. This furnace isconstructed similar to the furnace 6 but is longer than furnace 6, sinceit is used to raise the temperature of the work pieces an appreciableamount. This furnace is constructed in accordance with ordinary furnacepractice and is provided with a narrow entrance, shaped to fit theshells, which leads into a narrow elongated furnace chamber 85 that isheated by a plurality of burners 86 located in the side walls thereof.These burners are preferably of the type disclosed in Hess Patent2,215,079. The work leaves the furnace through a narrow exit 87. It isnoted that this furnace, as well as furnace 6, is provided with a slot88 in the bottom thereof through which the work holders 25 project asthey move through this portion of the path. It is also noted that theconveyor is covered for the extent of the furnace by means of a watercooled duct 89 which serves to prevent transfer of heat from the slot tothe conveying mechanism.

As work leaves the furnace 8, it passes immediately into an air coolingzone 9 which extends for a relatively long distance along the conveyor.This zone consists of a duct 91 through which air is forced by the fan11, which duct is located, as best shown in Figure 8, on one side of thework. Opposite the duct is a shield 92. Air is blown from the ductthrough a slot 93 that extends along the lower portion thereof, so thatthe air is directed over the surface of the work as well as into thecavity formed in the interior thereof.

As the work leaves the air cooling zone, it passes into a water coolingzone 12, best shown in Figure 9. Extending under this zone is a Watertank 94 from which water is pumped by a pump 95 through a pipe 06 to aplurality of spray nozzles 97 on one side of the conveyor and 8 on theopposite side thereof. Water is sprayed over the work as it passesthrough this zone in order to cool the work down to handlingtemperature.

There is provided a shield around the work pieces while they are in thiszone to prevent the spray from getting on the surroundings. To this end,there are provided side pieces 99 and 101 on each side of the spray andend pieces 102, the latter of which are provided with openings throughwhich the work can pass. Water striking against the shields flowsdownwardly to a collecting pan 103 and from this pan to the tank 94. Ashield is provided to insure that water flowing from the pan will gointo the tank. If it is found to be desirable, some suitable form ofliquid level control can be used to control the level of the liquid intank 94 and to control the replacement of water that is lost byevaporation or otherwise.

After the work leaves the water cooling zone, it is moved to a positionin front of an unloading platform 105 which is shown herein as comprisedof a plurality of rollers down which the work can move by gravity whenthe work carriers are lowered to a position slightly below thehorizontal as shown in Figure 10. At this station, there is provided amechanism to move the work carriers from their vertical position totheir lowered position which is determined by an extension of the rail45. This lowering mechanism includes a plunger 106 to move the worksupport in a clockwise direction until the projection 24 thereof can beengaged by a further lowering mechanism 107. The lowering mechanismshown in Figure 10 operates in the same manner as that described abovein connection with Figure 6 to lower the work into the quench tank. Itis noted that the various mechanisms used to raise and to lower the worksupports are similar to each other and operate in the same fashion.Those shown in Figure 10 and Figure 5 have the actuating piston disposedvertically and those shown in Figure 6 and at the end ofthe quench tankhave the actuating piston disposed horizontally. This change in theposition of the piston is necessitated by the space limitations of theapparatus.

' After the work holders pass beyond the unloading station 13, they stayin their horizontal position as they move around sprocket 2 to theloading station. Track 4-5 gradually moves these work holders from thelower than horizontal position shown in Figure 10 to the substantiallyhorizontal position shown in Figure 5 where the operations are repeatedfor a new cycle.

The operation of the apparatus should be apparent from the abovedescription. A short summary, however, will be given.

If the work is already hot, such as work moving directly from a forge,it will be placed on the work holders at the last station on the loadingplatform 57 shown in Figure 1. Work at this station will be in theneighborhood of 1550 F. The work will then be moved to its verticalposition and carried immediately into the furnace 6 where itstemperature will be balanced throughout its entire section and will beraised perhaps or so. Immediately thereafter, the work is moved into thequench tank which will reduce its temperature to a range between 200 F.,and 300 F. After the work is quenched, it will be tempered by thefurnace 8 which brings its temperature to approximately 1200 F., orslightly below the critical temperature. This reheated work is cooled bythe air flowing from duct 91 to about 600 F., and is spray cooled instation 12 to approximately F., at which temperature it can be readilyhandled by an operator. The various heating and cooling devices are ofsuch a length and are maintained at such a temperature that thetemperature of the work pieces is changed the required amount during thetime required for them to move through the respective devices. Theoperations are entirely automatic, since the various lowering andraising mechanisms are to be operated periodically in synchronism withthe operation of ratcheting mechanism that rotates sprocket 4. Suchsynchronous operation can easily be obtained by those skilled in the artby operating solenoid valves, for example, that are placed in the airinlet lines to the various pistons with these valves being energized anddeenergized as the sprocket 4 is stepped around. It will be apparentthat the work holders 25 on the ends of the arms 23 can take other formsthan the bar shown herein, in order that they may accommodate workpieces of different shapes. It is also apparent that the entrance to thefurnaces could be shaped to accommodate work pieces of different shapes.

In the above description, it was assumed that the work pieces placed onthe work holders at loading platform 57 were already heated to a certaindegree. It will be apparent, however, that cold pieces could be placedon the holders at this point if it was so desired. In such event,furnace 6 would have to be made long enough to raise these pieces to thedesired temperature.

While in accordance with the provisions of the statutes, we haveillustrated and described the best form of embodiment of our inventionnow known to us it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit and scope of the invention as set forth in theappended claims, and that in some cases certain features of ourinvention may be used to 7 advantage without a corresponding use ofother features What is claimed is:

1. In apparatus for operating successively upon a plurality of articles,the combination of a conveyor movable through a closed horizontal path,a plurality of article supporting members carried by said conveyor,means to mount each of said members on said conveyor for pivotalmovement relative thereto from a normal substantially vertical positionto a second position at an angle to the vertical, said mounting meansincluding a pivot and means to hold said members on opposite sides of avertical plane extending through said pivot when in their respectivevertical positions and second positions whereby said members will stayin either position when moved thereto, mechanism located adjacent tosaid path including means to move said members out of the verticalposition and means to control movement of said members to said secondposition, means extending adjacent to said path and engaged by saidmembers to determine said second position, additional mechanism locatedadjacent to said path to move said members from said second position tothe vertical position, and means to operate on articles carried by saidmembers in both positions thereof.

2. In a heat treating apparatus, the combination of a conveyor includinga plurality of carriages moving through a closed horizontal path, aplurality of work supports, means to mount one of said supports on eachcarriage for movement relative thereto from a normal vertical positionto a second position below the horizontal, said mounting means includinga pivot on each carriage around which a support moves, said pivot beingso arranged relative to each carriage and support on said carriages thatsaid supports will remain in either position when moved thereto, aplurality of heat treating work stations located at spaced points alongsaid conveyor, some of said stations receiving said supports in avertical position and other of said stations receiving said supports intheir second positions, means located in front of said stations to movesaid supports on said carriages to the position 'in which they arereceived by the station they are approaching, and means to actuate saidlast mentioned means.

3. In heat treating apparatus, the combination of work advancing meansmovable through a path, a first heating means located at one point abovesaid path, a quench tank located beyond said first heating means andbelow said path, a second heating means located beyond said quench tankabove said path, carriages attached to said advancing means and carriedthereby through said path,

a work holder pivoted to each carriage, means located at a point infront of said first heating means to move the work holders around thepivots on said carriages into a position above said path to enter saidfirst heating means,

means located adjacent to said path between said first heating means andsaid tank to move the work holders around the pivots on said carriagesto a position below said path in which they are immersed in said tank,and means located adjacent to said path and located adjacent to the endof said tank to move said work holders around the pivots on saidcarriages out of said tank and into a position above said path to entersaid second heating means.

4. In heat treating apparatus, the combination of a conveyor travelingin a closed horizontal path, a quench tank located beneath a portion ofsaid path, a plurality of carriages attached to and traveling with saidconveyor, a work holder extending normally in a vertical direction, ahorizontal pivot by means of which a work holder is pivoted to eachcarriage, mechanism located beside said conveyor adjacent to theentrance end of said quench tank including as a part thereof means tomove said work holders in a vertical plane around their pivots fromtheir normal position to a position below said conveyer in whicharticles carried thereby will be immersed in said tank, means in saidtank to maintain the articles on said work holders, means also in saidtank to limit the movement of the work holders around their pivots onsaid carriages, and mechanism located beside said path adjacent to theexit end of said quench tank to movesaid work holders back to theirnormal vertical position.

5. In apparatus for heat treating metal, the combination of means tomove a plurality of work pieces through a path including a chain, meansto advance said chain, tracks located adjacent and parallel to saidpath, a plurality of carriages movable along said tracks, means toconnect said carriages at spaced points to said chain to be movedthereby, work holding members pivoted to said carriages, said membershaving a normal predetermined position With respect to saidcarriages,'means located at a predetermined point along said path tomove said work holders out of said normal position to a second position,additional means located at another predetermined point along said pathto move said work holders back into said normal position and a coverextending over a portion of said track and the carriages thereon, thepivots between said carriages and the work holders being below and toone side of said tracks, said work holders being so shaped that theyextend upwardly from said pivots and inwardly above the cover over saidcarriages.

6. The combination of claim 5 in which the normal position of said workholders is vertical, and in which said second position of said workholders is substantially horizontal whereby to facilitate the loadingand unloading of work pieces thereon, and mechanism to perform work onthe work pieces on said work holders as they are traveling between saidtwo moving means.

7. In heat treating apparatus, the combination of an endless conveyermoving through a fixed path, means to advance said conveyer through saidpath in a sequence of steps, a plurality of workholders, means to mountsaid holders at spaced points on said conveyer for pivoted movement in aplane substantially perpendicular to the direction of conveyer travelfrom a vertical position through a dead center position to asubstantially horizontal position, the weight of said holder maintainingit in its vertical or horizontal position, a plurality of heat treatingdevices located along said path and adapted to treat work carried bysaid holders in their vertical and their horizontal positions, and meanslocated adjacent to said conveyer at points in advance to said devicesoperative to move said holders to the position in which work thereon canbe treated.

8. The combination of claim'7 in which said moving means is located tomove said workholders when they are at rest between the step movementsof said conveyer.

9. In heat treating apparatus, the combination of a track extendingthrough a path, a plurality of carriages on said track, each carriagehaving a portion extending below and toward one side of said track, awork carrier pivoted to said portion and being so formed that it extendsaround said track to a position above said carriage toward the otherside thereof, the weight of said carrier holding it in that positionwith a part thereof extending vertically, means located on the oppositeside of said track from that toward which said portion extends operativeto move said carrier out of its vertical position, to an extent where itcan fall around its pivot, means to control the downward movement ofsaid carrier, and means to limit said movement.

10. The combination of claim 9 including means to return said carrier toa position in which said part is vertical, said means being locatedbeside said track and beyond said first means in the direction ofmovement of said carriage along said track.

11. In a heat treating machine, a heat treating device, a pair of railsextending through a path past said device, a carriage movable on saidtracks, a workholder,

means to mount said holder on said carriage for movement in a directionsubstantially perpendicular to said path from a normal vertical positionthrough a dead center position to a position substantially horizontal,cooperating means on said holder and carriage to determine exactly saidvertical position, means located beside said track to move said holderfrom its vertical position through its dead center position whereby itcan fall to its horizontal position, means to control the movement ofsaid holder as it is falling, means to determine said horizontalposition, and additional means located along said path beyond said firstmeans to move said holder from its horizontal position through its deadcenter position whereby it can fall to its vertical position.

12. The combination of claim 11 including means to hold Work on saidwork holder when it is in its horizontal position.

13. Heat treating apparatus comprising in combination a conveyertraveling through a closed horizontal path, a first heat treating deviceabove and aligned with said conveyer, a second heat treating devicebelow and to one side of said conveyer, a carriage on said conveyer, aworkholder having a portion normally extending vertically above saidcarriage and a portion off-set to one side thereof, means to pivot saidofi-set portion of said workholder to said carriage at a point adjacentto one side thereof and for movement in a plane perpendicular to thepath of carriage travel, adjustable means between said carriage andofi-set portion to determine the normal position of said verticalportion, means operative to engage said vertical portion and move saidworkholder around said pivot so that it may extend to the side of saidconveyor on which said second device is located, means to align saidworkholder to travel through said 10 second device as said carriagemoves with said conveyer, and means located beside said conveyer toreturn said workholder around said pivot to its normal vertical positionaligned with said first device.

14. Heat treating apparatus comprising in combination a conveyer movingthrough a horizontal path, first and second heating devices located atspaced points along said path and vertically above said conveyer, aquenching device located along said path between said devices and to oneside of said conveyer, a carriage on said conveyer having a partprojecting toward said side, a workholder on said carriage having avertical portion centered with respect thereto and a portion ofi-settoward said side, means to pivot said ofi-set portion to said part ofsaid carriage whereby said holder can move on said carriage from avertical position aligned with said heating devices to a position to theside of said conveyer aligned with said quenching device, means tolocate accurately said holder in said positions, means located alongsaid path ahead of said quench device to move said holder from itsvertical position to its position aligned with said quench device, andmeans located along said path ahead of said heating devices to move saidholder into its vertical position aligned with said heating devices.

References Cited in the file of this patent UNITED STATES PATENTS383,030 White May 15, 1888 1,783,155 Talley Nov. 25, 1930 2,322,777Purnell June 29, 1943 2,393,521 Duncan et al. Ian. 22, 1946 2,504,815Detuno Apr. 18, 1950 2,548,683 Remington et al. Apr. 10, 1951 2,642,212Currivan June 16, 1953

